Fuse



April 1,1925. 1,532,369

F. W. BOLD FUSE Original Filed 001;. 1919 /7 f 44% iziflqgl Patented W- FREDERICK W. BOLD, 0F CEA,

MASSACHUSETTS, ASSIGNOR T0 CHARLES H.

PEARSON, 0F BROOKLINE, 'MASSACSETTS.

FUSE

original application filed October 31, 1919, Serial No. 334,849. Divided and this application October 26, 1921. Serial No. 510,529. Renewed July 1, 192

To all whom it may concern.

Be it known that I, FREDERICK V. Bonn, a citizen of the United States, and resident of Chelsea, in the county of Sufiolk'and State of Massachusetts, have invented an improvement in Fuses, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My present invention relates to mechanical time fuses, and more particularly to mechanical time fuses adapted to be applied to ordnance shells for the purpose of detonating the charge therein after a predetermined length of time following the discharge of the shell from a gun.

ln fuses of this character, no great difficulty has been experienced in the past in devising means to positively detonate the charge in the shell. Considerable difliculty, however, has been experienced in devising means that will admit of the charge being detonated at exactly the right time, that is, means that will detonate the charge when, and only when,. it should be deto nated. In other words, a mechanical time fuse. to be satisfactory, must be safe to handle with the assurance that nothing short of its discharge from a gun, or by dropping it from such a distance that the shock or impact will be equal to its discharge from a gun, or an equivalent shock, will place the mechanism of the fuse in operative position, or in condition to detonate the charge of the shell to which it may be attached.

Mechanical time fuses of this character must be strong enough mechanically to Withstand the shock of discharge and the tremendous centrifugal forces set up by the rotation of the shell after discharge. That such strength is essential will be obvious when it is understood that the shock of discharge is so great that it is generally accepted that the inertia of each grain of weight of the fuse becomes equal to approximately two pounds; that is, the apparent weight of the fuse is equal to its actual weight multiplied some fourteen -thousand times. The centrifugal force set up by the rotation of the shell is such that at a distance of approximately fiveeighths of an 111011 from the axis of the fuse such centrifugal force is approximately equal to the force due to the shock of firing.

As a time fuse, when attached to a shell,

has its time train always in operative con-- dition, it' is essential that means be provided to prevent accidental starting of such time train, with the resulting disastrous effects, until the desired predetermined length of time after such starting.

.The principal object of my present invention is the provision of means associated with the time train, to prevent the startmg of the timing train until the fuse has been subjected to the shock of firing.

Other objects and novel features of the construction and arrangement of parts compr1sing my invention will appear as the description of the invention progresses.

The invention forming the subject-matter of the present application is fully disclosed in my copending application Serial No. 334,849, filed October 31, 1919, of which the present application is a division. In the accompanying drawings ,illustratong the preferred embodiment of my inven- Fig. 1 is a sectional elevation of a fuse to which my invention has been applied;

Fig. 2 is asectional plan view on the line 2-2 of Fig. 1, i

Fig. 3 is an enlarged fragmentary view of a portion of a timing train, showing my invention, and

Fig. 4 is an enlarged sectional detail, showing the means for locking the clock starting mechanism.

Referrin to the drawings, 10 designates the fuse lock, provided with exterior threads 11 by means of which it may be attached to a shell, and with a priming chamber 12 on its lower end, this chamber being closed by the screw plate 13. A passage 14: extends from the priming chamber 12, to a depression 15, located in the upper portion of the fuse block 10 and in which is placed the primer 16. The upper face of the fuse block is recessed at 17 to receive the lower plate 18 of the clock or timing movement 19. Screws 20 hold the movement firmly in posi-' tion in such recess. A portion of the bottom face of the recess 17 is cut away to form a chamber 21 exposing the upper portion of the depression 15, in which is located the ing located below the middle plate primer 16. Pivotally mounted on the lower face of the chamber 21 is a plate or shutter 22, held in normal position, or in the position to cover the depression 15, by a spring (not shown).

The clock or timing movement 19 comprises the bottom plate 18, middle plate 25, and top plate 26, spaced apart from each other by a plurality of pillars 27 and 28, re-

spectively, and a cover plate 29 is secured to the top .plate 26. The center staff 30 is mounted in bearings in the middle plate 25 and cover plate 29 and mounted on said staff, and ordinarily rotatable with respect thereto, is a hub 34, at the bottom of which is staked, or otherwise secured, a gear 35 meshing with a pinion (not shown) associated with the portion of the timing gear- 25. As the construction and arrangement of such portion of the'timing gearing forms no part of the present invention, it will not be described in detail herein. On the hub 34 and above the gear wheel 35 is staked an arm or release lever 33, which extends laterally from the hub and is rotatable therewith. Staked to the upper end of the staff'30 is a setting plate 62, provided on its periphery with a notch 67 into which the extension 68 of the release lever 69 moves to release the firin pin 41. A rod or shaft 70 mounted para lel to the staff 30, in the top and bottom plates 26 and 25 respectively, is provided near its lower end, with a tapered portion 71 and slidably mounted on the rod or shaft 70 is a sleeve 72, the lower portion of the bore of which is tapered to correspond with the taper 71 on the rod or shaft 70. The upper ortion of the sleeve 72 is grooved at 73 whic en ages with the outer end of the arm 33.

vents, under normal conditions,

e sleeve 72 engaging with the arm 33, prevents said arm, and therefore the timing train, from rotating, while the arm 33 engaging in the groove 73, prothe separation of the sleeve and arm. When the shell is fired from a gun, the shock of firing forces said sleeve downward along the rod'or shaft 70 into the position shown in Fi 4, and releasing it from the arm 33. train thereupon starts, and, what is of great importance, the sleeve 72 wedges itself onto the tapered portion 71 of therod or shaft, and preventing the rebound of the sleeve with the consequent liability of stopping the timing train.

As my invention relates to a type of device that is intricate in character, I have necessarily described the preferred embodiment thereof somewhat in detail. It is to be understood however, that I may vary the construction and arrangement of the elements constituting my invention within wide limits without departing from the spirit thereof.

Having thus described my invention, what I claim as new, is

A starting means for the timing train of a mechanical time fuse comprising, in combination, a radially extending arm fixed to the timing train, a shaft, a sleeve slidable longitudinally of said shaft and normally engaging the end of the radially extending arm, said sleeve movable on said shaft out of engagement with said arm on theshock of firing, and cooperatin means on said shaft and said sleeve for ocking the sleeve to the shaft on the shock of firing.

In testimony whereof, I have signed my name to this specification.

FREDERICK w. BOLD.

he timing- 

